Air ejector



Jan. 12 1926. 1,559,760

c. L. A. M. LEBLANC AIR EJEcToR Fi1ea sape-.119, 1922 va: sheets-sheet 1 A? Mm/@d Y ./Lgmr'w Jan. 12 1926. 1,569,760.

C. L. A. M. LEBLANC un EJEcTon I Filed 1922 3 Sheets-Sheet 2 /N VEA/TOR Jan. l2 1926. 1,569,760

c. L. A. M. LEBLANC v AIR EJEGTOR Fiied sept. 19, 1922 5 ysums-sheet s .Mjah mw www Patented Jan. 12, 1926.

UNITED CHARLES-LEONARD ARMANnMAUnIOE LEBLANC, OE rAaIs'; FRANCE, A'ssIeNoR ,fro SOCIETE ANONYME POUR LEXPIJOI'JJAIION Das rRooDEs MAURICE LEBLANC- VIcKERs, `or PARIS, FRANCE..

AIR EJEGTOR.

Appucat'ibn area september i9; 1922,' seria-1m. stair?.l

To aZZ whom t may concern.' y p Be it known that I, CHARLES LEONARD ARMAND MAURICE LEBLANC, a citizen of France, and a .resident of Paris, France','have invente-'d Certain new and useful Improvements Relating to Air` Ejectors, which is fully set forth in the following specilication. rlhe present invention relates to a steam y operatedairejector othigh power and cornprisingz` ay plurality` of sections, ymore vvparti'culalrlyv applicable to condensersLV of large capacity, suchy as are used With high power steam turbines." l f This compound ejector has the` 'lol-lowing essential characteristicszf 1. The .grouping of severalsections or elementary Ordinary ejectorsin tivo stages upon a single condenser.

2; The constitution of vthis single con- 1. Regulation of the apparent expendi-` ture of live steam in proportion to the 'Weight of air tO be' extracted, which varies with the rate of Working; of the plant, and moreparticularly `With the load on the turbine, it' a turbinesetis concerned.

tained in the exhaust steam.- V

3." Prevention of .the earryingover of uncondensible gases into the' Water tank, their a'dinixture With the feed-Water for the boil- 'ev-rs', and the 'drawbacksresulting-therefrom. Y Simplificationkk ofV theflay-out of pipes required for titting'up the plant, which" is equivalent to several single apparatus Tvorking in parallel. j 4r?k :5. Relieatingof the'feed Waterby the twin v,interm-e'diate condenser, owing4 to the Afact that thi: s flatter. is locatedf on the'delivery vpipev from the extraction pump to the -Water tank. A 1 The yc'jllnviiop; vdescription witl'i reference to the accompanying*drawings, "Whichl are givenby'ivay of example', Wi'llmake cleal1 tlietnature andv` thev fadvantagfes of the inven tionL Y l f denser by tifvoelemeii'tary surface condensersl 2. Recovery of the Whole of the heat con- Figs. 1', 2jandv3 show respectii'fely'a'V side elevation, an end view and aplan'of a cornpound steam .ejector with a ,plurality v,of sections, constructed in accordancewith this,|

invention.

' Fig. lf-is a. longtu'dinalsection on the' line I'V- IV OftFig. 2f .y f

Fig; 5 isla cross-.section on the lineV-7 of Figs. 1 andS.

Fig.f6 is a'cross section on the `line 'VI-VI of Figs. 1 and 3. v v

Fig'. .7 isa horizontal ysection'on' the line 'VTT-Vliet Fig. 4: v 1- F ig. 8 is a' general diagram of aplant in which such a compound' ejector is applied to the extractionoffair from a condenser, for exanipldof a steam turbine.

As seen the apparatus, objectofthis rinvention, comprises essentiallv ltwo groups A1 and' A42 of elementary ejectors (three ej ectors` per group in tlie example shown) provided ywith interme'diaryI surfacel condensyers'C'1 and C2 respectively,'Whichare interl The air iswitlrdrawn, for example `rfromv the main condenser,^throughfthe connecting branch @common to`v the 'set offfirst ystage ejectors A, ,the operative steam is yadmitted at to the ejectors ot' :thisstageyafterlravi l 1,569,760 rArsN'I i o Fries,A L

ing subjected the air into a first compression, it passes into `the correspond,ing'.vcondenser 1. A

` Thiscondenser C, isjfomned'ottwobund'lesof tubes D1 and El, througlrwliiclr the i again at d and Withdrawn'by-they ejectors A2 of' the second stage group, the operative steam frWbiclris admitted at e.'- Ai'ter `doing its wor-lr thisfst'eain passes into-the' condenser'v Cg, similar to ,the- :'r'st' con-denser^` G1 except thatl it has no partition-. The'air'carried over and c'on'ipress'eda secondfti'meescapes into' theat'mosphere'througlijthefcon nectin'g branch g.'

` f kThe lbundlf-s of tubes 'ofi the; 'eondensers C1 and`- C, ar'e' v cooled )by the lwvalter" coming from the extraction pump of the main condenser Gr (Fig 18)? The stream off'vva-ter enters at 72. andl escapes at It traverses the' tivin condensersG'l- C2. in a fsystem- 'atie way, being heated first in C1 by contact with the steam from the first stage, and then in C2 by contact with the steam from the second stage (Figs. l to 7).

The condensation of the steam in the condensers C, and C2 is systematic, and effected on the contraflow principle. The steam coming from the ejectors thus reaches the tubes traversed by the least cold water; this is why the escape from the first stage elementary ejectors A1 enter the inner tubes D1 of the condenser C, whilst the escape from the second stage elementary ejectors A2 enters the outer tubes E2 of the condenser C2.

The condensatie in C, returns to the main condenser G (Fig. 8) through a U tube Z, attached to the branch j; the steam condensed in G2 is drawn olf through the branch 7c which is connected to the lowest point of the deliverypipe m to the water tank J.

Owing to the plu 'ality of members it is possible, once the turbine has been started up and reached its normal working, to shut the steam admission valves on one or more members of the compound ejector, and thus to obtain an economy in consumption.

It is to be noted, in fact, that the quantity of air` to be extracted decreases on load, and consequently also the strictly necessary expenditure of steam.

The arrangements made on the other hand allow of the complete recovery of heat units Y sinceboth the exhaust steam of the second stage A2 and of the first stage AL, is condensed by heat exchange through the tubes of the twin condenser C, C2, and since the cooling water carries ofi' the water tank J the whole of the heat contained in this steam.

The only loss is that caused by the re turn to the main condenser Gf of the condensate from theexhaust steam from the first stage A,. This loss is unimportant, since it is numerically equal, per kilogramme of steam used in the first stage, to the difference of temperature Vbetween the main. condenser G and the intermediate condenser C, of the ejector, and thus amounts to about l5 calories.

l The surface condensation of the exhaust steam from the second stage A, of the tubes prevents the carrying over of the extracted air to the water tanks and consequently the serious drawbacks which are caused for the boilers bythis carrying over.

Finally the compound ejector with` a plu rality of sections serves the same purpose as several ordinary `aqaparatus working in parallel, in particular it completely assures the working of the .plant to which it is attached inthe case of the breakdown of any one of the sections.

This advantage is obtained by means of a simple layeont for erection as shown in the diagram, Fig. 8, which permits of obviating the complicated system of pipes necessitated by the usual plan.

In Fig. 8, KMX is the licor Vline of the engine room, G the main condenser, L the extracting pump, Z the U'tube acting as draw off for the first stage condenser C1, J the feed water tank, m the feed water return pipe, n the draw off for the second stage condenser C2, 0 the air suction pipe into the main condenser G, J the air escape pipe from the twin condenser C1 C, and Q the escape to' the atmosphere.

The operation of the compound ejector with a pluralityof sections as applied for example to a steam turbine condenser is as follows 1. Admission of live steam to all the second stage ejectors A2. During this period, the steam exhausts to the atmosphere.

2. When the Vacuum in the main condenser C reaches about GOO mm. the turbine is started up, and then the condensing plant i. e., the pump L. The twin condenser C1 C2 of the ejector is then traversed by the cooling water.`

3. Admission of live steam to all the ejectors of the first. stage A1.

4. When the vacuum in the main condenser G reaches its maximum, simultaneous closing of lirststage and second stage steam valves of one or more sections of the ejector, according" to the weight of air to be extracted.

As follows from the explanation already given, the compound steam operated ejector the object of t-h invention conduces to the following advantages l. Regulation of the apparent expenditure of live steam in proportion to the weight; of air to be extracted, which varies withthe rate of working of the plant, and more particularly with the load on the turbine, if a turbine set is concerned.

2. Recovery ofthe whole of the heat contained in the exhaust steam. y

3. Prevention of the carrying over `ofuncondensible gases into the water tank, their admixture with the feed water forthe boilers, andthe drawbacks resulting therefromt Ll. Simplification ofthe'lay-out of pipes required for fitting up the plant, which is equivalent to several single apparatus working in parallel.

5. Reheating of the feedwwaler by the twin intermediate condenser, owing to the fact that this latter is located on the deliv ery pipe from the extraction pump to the water tank. i

lt is to be understood that the arrangements which have been givenbylway of example in no way limit the invention, and that modifications may beV made therein without going outside its ambit,

Especially it is obvious that the funda l no lll)

ond stage by mere bubbling through thel water tank, and at the iirst stage by admixture 1n an injector condenser. However, in the former case the benefit of eliminating air would be lost, and in the latter case that ofk complete recovery. That I claim is 1. rlhe combination with a main condenser of an airextractor including two stages of steam ejectors mounted in series, each ot said stages including a plurality of ejectors mounted in parallel, means for supplying steam to either or both of said ejector stages,a first auxiliary condenser associated with one of'said ejector stages and comprising concentric bundles ofwater tubes, a partition separating ysaid bundles of tubes, means for directing water from said main condenser through the outer bundle of water tubes and thence throughthe inner bundle of water tubes, means for directing steam from said iirst stage of ejectors into the inner bundle oi' water tubes and thence to the outer bundle of water tubes,` a second auxiliary condenser associated with the'other of said ejector stages and comprising two concentric bundles ot water tubes, means for direct-ing water from said first condenser to the inner bundle of tubes of said second con denserand thence to the -outeibuiidle ot tubes ot said second condenser'aiid means Vfor directing steam from the otlierfstage of steam ejectors into the outer bundle of water tubes oi said second condenser.

The combination with a main condenser of an air extractor including two stages or" separating said bundles of tubes, means forl directing waterk from said main condenser through the outer bundle of watertubes and, thence through the inner bundle of `watery tubes, meansrlor Vdirecting steam from said iirst stage of ejectors into the inner bundle of water tubes and thence to the outer bundle o-water tubes, a second auxiliary condenser associated with the other of said ej ec# tor stages and comprising two concentric bundles or water tubes, means directing Vwater from said liirst condenser to the inner bundle of tubes of said second condenser and thence to the outer bundle of tubes of said second condenser, means `tor directing steam from the other stage of steam vejectors into the outer bundle of water tubes of said sec-- ond condenser, the tubes of said second auxiliary condenser forming prolongations of the tubes of the first condenser. anda vcommon casing surrounding said auxiliary condensers.

8. The combination in an air extractor of two steam ejector stages connected in series, two sets oi condenser tubes disposed in line within a common casing, land plates for each sov of saidv lsets of tubes,a cylindrical partition separating one of said sets of tubes into two bundles and extending from a point adjacent the outerl end plateot said set of tubestothe inner end plate of the other set of tubes, an annular partition between said sets of tubes,

a: water inlet between said lirst set of tubesY and said annular partition, awater outlet between said second set of tubes and said annular partition, means toi' directing steam from one of said ejector stages to the bundle of tubes within said cylindrical. partition, an outlet for uncondensedfgases from said first set of tubes, means for admitting steam from said second ejector stage kto t-he other set of tubes and an outlet forsaid steam.

In `testimony whereof I have signed this specification. U f

CHARLES LEONARD ARMAND MAURICE LEBLANC. 

